Abstract:
RESEARCH PROJECT (LAB 14) DELICATE CRYSTAL GROWTH IN GELS. John Micevych. The purpose of this research project was to discover the effects of certain conditions on the growth of delicate copper crystals in a sodium silicate gel.By altering the temperature, type of metal, and amount of surface area, data was collected that provided evidence towards the conditions that would create the most, largest, fastest growing, and most well-defined crystals.In order to optimize the oxidation-reduction reaction between the copper ions in the gel and the metals’ atoms, it was concluded that magnesium was the most reactive (best tendency to give away electrons), higher temperatures produced faster and more crystal growth, and solid pieces of the metals were better than granulated because they sustained growth much more effectively.
Room temp, solid piece (2 tubes were run at theses conditions)
40 C, solid piece
7 C, solid piece
Size of crystal
Fairly large
Very Large
Small
Definition of crystal
Well-defined
Well-defined
Somewhat defined
Speed of formation
Fast
Very Fast
Slow
Amount of crystals
Somewhat many
Many
Somewhat many
Table 4: Tin
Conditions
Room temp, granulated
Room temp, solid piece
7 C, solid piece
40 C, granulated
Size of crystal
Small
Very large
Large
Small
Definition of crystal
Badly defined
Very well-defined
Fairly well-defined
Badly defined
Speed of formation
Fast
Fast
Slow
Very fast
Amount of crystals
Many
Some
Not many at all
Very many
Table 5: Zinc
Conditions
Room temp, granulated
Room temp, solid piece
7 C, solid piece
40 C, granulated
Size of crystal
Small
Medium -sized
Small
Small
Definition of crystal
Very badly defined
Not very defined
Badly defined
Very badly defined
Speed of formation
Somewhat quickly
Slow
Slow
Fast
Amount of crystals
Many
Not many
Not many at all
Somewhat many
Scientific Journal Summary: Crystal structure prediction using ab initio evolutionary techniques:
Two researchers at the Laboratory of Crystallography of the Department of Materials in Zurich, Switzerland have developed an efficient and reliable technique for predicting crystal structure.By utilizing ab initio, or total energy, calculations and an innovative evolutionary algorithm, they have come up with a method for discovering the most stable crystal structure for compounds at any pressure or temperature setting.In order to locate the global minimum of the free energy surface, which would result in the most stable structure, the researchers decided to apply their technique not to the entire surface, but only to a small, promising area.From there, they can use a self-improving method that continually locates more stable structures.This is specifically groundbreaking because it requires no experimental data, unlike most of the other techniques being investigated in laboratories across the globe.The algorithm has worked on both ionic and covalent compounds of varying complexity.In addition, it provides an opportunity to test crystal structures at conditions so extreme that they cannot yet be replicated on Earth.In the tens of tests completed so far, the researchers report a success rate that is almost 100%, further validating their method.
Oganov A., Glass C. 2006. Crystal structure prediction using ab initio evolutionary techniques: principles and applications. The Journal of Chemical Physics. 124(1):1-15.
RESEARCH PROJECT (LAB 14) DELICATE CRYSTAL GROWTH IN GELS. John Micevych. The purpose of this research project was to discover the effects of certain conditions on the growth of delicate copper crystals in a sodium silicate gel. By altering the temperature, type of metal, and amount of surface area, data was collected that provided evidence towards the conditions that would create the most, largest, fastest growing, and most well-defined crystals. In order to optimize the oxidation-reduction reaction between the copper ions in the gel and the metals’ atoms, it was concluded that magnesium was the most reactive (best tendency to give away electrons), higher temperatures produced faster and more crystal growth, and solid pieces of the metals were better than granulated because they sustained growth much more effectively.
Key Words: crystal, crystal lattice, oxidation-reduction reaction, ions, atoms, surface area
Summary Graphic:
Table 3: Magnesium
Table 4: Tin
Table 5: Zinc
Scientific Journal Summary: Crystal structure prediction using ab initio evolutionary techniques:
Two researchers at the Laboratory of Crystallography of the Department of Materials in Zurich, Switzerland have developed an efficient and reliable technique for predicting crystal structure. By utilizing ab initio, or total energy, calculations and an innovative evolutionary algorithm, they have come up with a method for discovering the most stable crystal structure for compounds at any pressure or temperature setting. In order to locate the global minimum of the free energy surface, which would result in the most stable structure, the researchers decided to apply their technique not to the entire surface, but only to a small, promising area. From there, they can use a self-improving method that continually locates more stable structures. This is specifically groundbreaking because it requires no experimental data, unlike most of the other techniques being investigated in laboratories across the globe. The algorithm has worked on both ionic and covalent compounds of varying complexity. In addition, it provides an opportunity to test crystal structures at conditions so extreme that they cannot yet be replicated on Earth. In the tens of tests completed so far, the researchers report a success rate that is almost 100%, further validating their method.
Oganov A., Glass C. 2006. Crystal structure prediction using ab initio evolutionary techniques: principles and applications. The Journal of Chemical Physics. 124(1):1-15.